A toner cartridge, also called laser toner, is the consumable component of a laser printer. Toner cartridges contain toner powder, a fine, dry mixture of plastic particles, carbon, and black or other coloring agents that make an image on paper. The toner is transferred to paper via an electrostatically charged drum unit, and fused onto the paper by heated rollers during the printing process. An ink cartridge or inkjet cartridge is a replaceable component of an inkjet printer that contains the ink (and sometimes a print head) that is deposited onto paper during printing. Each ink cartridge contains one or more partitioned ink reservoirs. Certain manufacturers also add electronic contacts and a chip that communicates with the printer. Some ink and toner cartridges can be refilled.